The regulation of the PD-1/PD-L1 pathway in imiquimod-induced chronic psoriasis itch and itch sensitization in mouse.

PD-1/PD-L1 inhibitors have been demonstrated to induce itch in both humans and experimental animals. However, whether the PD-1/PD-L1 pathway is involved in the regulation of chronic psoriatic itch remains unclear. This study aimed to investigate the role of the PD-1/PD-L1 pathway in imiquimod-induced chronic psoriatic itch. The intradermal injection of PD-L1 in the nape of neck significantly alleviated chronic psoriatic itch in imiquimod-treated skin. Additionally, we observed that spontaneous scratching behavior induced by imiquimod disappeared on day 21. Still, intradermal injection of PD-1/PD-L1 inhibitors could induce more spontaneous scratching for over a month, indicating that imiquimod-treated skin remained in an itch sensitization state after the spontaneous scratching behavior disappeared. During this period, there was a significant increase in PD-1 receptor expression in both the imiquimod-treated skin and the spinal dorsal horn in mice, accompanied by significant activation of microglia in the spinal dorsal horn. These findings suggest the potential involvement of the peripheral and central PD-1/PD-L1 pathways in regulating chronic itch and itch sensitization induced by imiquimod.

The opposite effect of tapinarof between IMQ and IL-23 induced psoriasis mouse models.

Tapinarof is an aryl hydrocarbon receptor (AHR) ligand which is used to treat plaque psoriasis in adults. However, the underlying mechanism is not yet fully understood. In this study, we applied two of the most studied psoriasis mouse models: topical application of imiquimod (IMQ) and subcutaneous injection of IL-23. Although both models successfully induced psoriasis-like lesions in mice, tapinarof had a completely opposite effect on the two models. Tapinarof decreased the expression of multiple essential cytokines involved in the pathological IL-23/IL-17/IL-22 axis and ameliorated IMQ-induced psoriatic dermatitis, inhibiting keratinocyte proliferation and abnormal differentiation. However, in the IL-23-injection-model, tapinarof instead aggravated the disease. Here, tapinarof increased epidermal thickness and differentiated epidermal dysplasia in mice. Our data suggest that tapinarof may have different effects on varied types of psoriasis.

Penile intraepithelial neoplasia incidence, clinical classification, microenvironment and implications for imiquimod treatment.

OBJECTIVES: To provide an outline of the existing data on penile intraepithelial neoplasia (PeIN), as well as a narrative review on imiquimod (IQ; a toll-like receptor 7 agonist) treatment and immune microenvironment markers that may predict response to treatment. METHODS: A narrative review of the literature from 2000 to the present was conducted on PubMed, and we describe the most relevant data and cross references. RESULTS: The incidence of PeIN is increasing. Local therapy with IQ may offer an easy applicable treatment with complete response rates of up to 63% but can be associated with considerable side-effects. There is no conclusive data on the optimal treatment schedule for PeIN, but evaluation of treatment results for other human papillomavirus-related pre-malignancies suggest three times a week for a duration up to 16 weeks. There are no published studies concerning the PeIN immune microenvironment. However, findings from the few studies on penile cancer and pre-cancerous vulvar and cervical lesions imply that specific immune cell subpopulations can serve as future predictors for successful immunomodulation treatments such as IQ. CONCLUSIONS: Overall, limited data are available on IQ treatment for PeIN and no published data exists on the PeIN immune microenvironment. Further translational studies are warranted to gain more understanding on the pathophysiology of PeIN and potential predictors of progression and of response to topical treatments.

Is imiquimod a promising drug to treat oral mucosa diseases? A scoping review and new perspectives.

Imiquimod (IMQ) is a chemotherapeutic and immunostimulant drug that is applied topically, demonstrating antitumor and antiviral activities. The objective of this review was to compile data on the off-label use of IMQ in oral mucosal diseases. IMQ has exhibited effectiveness in the treatment of various oral mucosal conditions, including oral carcinogenic lesions, neoplasms, HPV-related lesions and autoimmune disorders. Although IMQ holds promise as a potential strategy for addressing oral mucosal lesions, it is important to note that significant side effects have been frequently reported. Nonetheless, it is crucial to develop and test new technological systems, such as the combination of nanotechnology with innovative drug delivery platforms. These advancements aim to minimize side effects and prolong the drug's contact time with the mucosa, preventing its removal by salivary flow.

Topical imiquimod treatment of residual or recurrent cervical intraepithelial neoplasia lesions (TOPIC-2): A randomised controlled trial.

OBJECTIVE: To investigate the efficacy of imiquimod in women with residual or recurrent cervical intraepithelial neoplasia (rrCIN), compared with large loop excision of the transformation zone (LLETZ). DESIGN: Randomised controlled non-inferiority trial. SETTING: One academic and one regional hospital in the Netherlands. POPULATION: Thirty-five women with rrCIN were included in the study between May 2016 and May 2021. METHODS: Women were randomised to receive treatment with 5% imiquimod cream (12.5 mg) intravaginally (three times a week for a duration of 16 weeks) or a LLETZ procedure (standard treatment). MAIN OUTCOME MEASURES: The primary outcome was reduction to normal cytology at 6 months after starting treatment. Secondary outcomes were clearance of high-risk human papilloma virus (hr-HPV) in both groups and reduction to ≤CIN1 in the imiquimod group. Side effects were monitored. RESULTS: Treatment success was 33% (6/18) in the imiquimod group versus 100% (16/16) in the LLETZ group (P < 0.001), whereas HPV clearance was 22% (4/18) in the imiquimod group versus 88% (14/16) in the LLETZ group (P < 0.001). After the randomisation of 35 women, the futility of treatment with imiquimod was proven and the trial was prematurely finished. In the follow-up period, three patients remained without additional treatment, whereas all other patients underwent LLETZ, conisation or hysterectomy. In the LLETZ group none of the patients received additional treatment during 2 years of follow-up. CONCLUSIONS: This is the first randomised controlled trial to show that topical imiquimod has a significantly lower success rate in terms of reduction to normal cytology and hr-HPV clearance, compared with LLETZ, in women with rrCIN. Additionally, imiquimod has numerous side effects and after using imiquimod most women with rrCIN still required additional surgical treatment.

Therapeutic outcomes and survival analysis of Extramammary Paget's disease: A multicentre retrospective study of 249 patients.

BACKGROUND: Evidence regarding long-term therapeutic outcomes and disease-specific survival (DSS) in Extramammary Paget's disease (EMPD) is limited. OBJECTIVES: To assess the DSS and outcomes of surgical and nonsurgical therapeutic modalities in a large cohort of EMPD patients. METHODS: Retrospective chart review of EMPD patients from 20 Spanish tertiary care hospitals. RESULTS: Data on 249 patients with a median follow-up of 60 months were analyzed. The estimated 5-, 10-, and 15-year DSS was 95.9%, 92.9%, and 88.5%, respectively. A significantly lower DSS was observed in patients showing deep dermal invasion (≥1 mm) or metastatic disease (P < .05). A ≥50% reduction in EMPD lesion size was achieved in 100% and 75.3% of patients treated with surgery and topical therapies, respectively. Tumor-free resection margins were obtained in 42.4% of the patients after wide local excision (WLE). The 5-year recurrence-free survival after Mohs micrographic surgery (MMS), WLE with tumor-free margins, WLE with positive margins, radiotherapy, and topical treatments was 63.0%, 51.4%, 20.4%, 30.1%, and 20.8%, respectively. LIMITATIONS: Retrospective design. CONCLUSIONS: EMPD is usually a chronic condition with favorable prognosis. MMS represents the therapeutic alternative with the greatest efficacy for the disease. Recurrence rates in patients with positive margins after WLE are similar to the ones observed in patients treated with topical agents.

Extramammary Paget disease. Part II. Evidence-based approach to management.

Extramammary Paget disease is a rare cutaneous malignancy that most commonly affects the genitals, perianal area, and axilla of elderly patients. Delays in care often lead to high levels of disease burden for patients. Thus, evidence-based recommendations are paramount in mitigating morbidity and mortality for this unique patient population. This 2-part continuing medical education series provides a complete picture of extramammary Paget disease. Part 2 of this continuing medical education series focuses on the complex management of extramammary Paget disease including surgical and noninvasive therapies, as well as novel approaches for advanced disease.

Protective effect and regulatory mechanism of salidroside on skin inflammation induced by imiquimod in psoriasis mice.

Salidroside (SAL) is a glucoside of tyrosol commonly existing in the roots of Rhodiola rosea. This study unveils the protective effect of SAL on skin inflammation in imiquimod (IMQ)-induced psoriasis. The mouse model of psoriasis was established by local application of IMQ, and SAL efficacy was evaluated through PASI scoring, H&E staining, and skin tissue pathology observation. The HaCaT cell model was established by interferon (IFN)-γ induction, followed by MTT assay detection of cell viability, detection of ROS, SOD, MDA, and CAT levels in skin tissues and cells using reagent kits, ELISA detection of inflammatory factors (TNF-α, IL-6, IL-1ß), and qRT-PCR detection of psoriasis-related genes (S100a9, Cxcl1, Cxcl2) as well as miR-369-3p and SMAD2 expressions. The binding relationship between miR-369-3p and SMAD2 was validated using dual-luciferase reporter assay. SAL treatment reduced PASI scores and alleviated psoriasis symptoms of IMQ-induced mice, and also augmented the viability and subsided the oxidative stress and inflammation of IFN-γ-treated HaCaT cells. SAL treatment restrained miR-369-3p expression but elevated SMAD2 expression. Mechanistically, miR-369-3p targeted SMAD2 expression. miR-369-3p overexpression or SMAD2 inhibition partially offset the alleviating effect of SAL on psoriasis skin inflammation. In conclusion, SAL alleviates skin inflammation in IMQ-induced psoriasis mice via the miR-369-3p/SMAD2 axis.

Successful management of chromoblastomycosis utilizing conventional antifungal agents and imiquimod therapy.

Chromoblastomycosis (CBM), a chronic fungal infection affecting the skin and subcutaneous tissues, is predominantly caused by dematiaceous fungi in tropical and subtropical areas. Characteristically, CBM presents as plaques and nodules, often leading to scarring post-healing. Besides traditional diagnostic methods such as fungal microscopy, culture, and histopathology, dermatoscopy and reflectance confocal microscopy can aid in diagnosis. The treatment of CBM is an extended and protracted process. Imiquimod, acting as an immune response modifier, boosts the host's immune response against CBM, and controls scar hyperplasia, thereby reducing the treatment duration. We present a case of CBM in Guangdong with characteristic reflectance confocal microscopy manifestations, effectively managed through a combination of itraconazole, terbinafine, and imiquimod, shedding light on novel strategies for managing this challenging condition.

Bombesin receptor-activated protein homolog deficiency altered the pattern of pathological changes of psoriasis - like skin lesion in mice.

This study investigated the potential role of the mouse homolog of bombesin receptor-activated protein (BRAP) in imiquimod (IMQ) induced psoriasis - like skin inflammation. The expression of both human BRAP, encoded by C6orf89, and its mouse homolog, encoded by BC004004, has been found to be expressed abundantly in the keratinocytes. BC004004 knockout mice (BC004004-/-) were topically treated with IMQ daily for 7 days to test whether they were more vulnerable to psoriasis - like inflammation. We found that those mice exhibited an altered pattern of inflammation process compared to isogenic wild type control mice (BC004004+/+). BC004004-/- mice developed skin lesions with earlier and more acute onset, as well as a quicker remission. The cytokines related to pathogenesis of psoriasis also exhibited different expression patterns in IMQ treated BC004004-/- mice. On day 4 of IMQ treatment, BC004004-/- mice exhibited a higher expression level of IL-17A compared to BC004004+/+ mice, suggesting a more robust activation of Th17 cells in the knockout mice. The serum level of thymic stromal lymphopoietin (TSLP), one of the keratinocyte derived cytokines, was also increased in BC004004-/- mice and reached its peak on day 4. Knockdown of BRAP in cultured human keratinocyte-derived HaCaT cells by siRNA silencing led to increased release of TSLP. Our data suggest that the elevated of level of TSLP released from keratinocytes due to BRAP deficiency might mediate the crosstalk between the epidermal cells and immune cells and thereby contributing to the altered pathological changes observed in psoriasis - like skin lesion in knockout mice.

Brilaroxazine lipogel displays antipsoriatic activity in imiquimod-induced mouse model.

BACKGROUND: Dopamine (D) and serotonin (5-HT) pathways contribute to psoriasis pathobiology. Disruptions incite increased inflammatory mediators, keratinocyte activation and deterioration, and worsening symptoms. Brilaroxazine (RP5063), which displays potent high binding affinity to D2/3/4 and 5-HT1A/2A/2B/7 receptors and a moderate affinity to serotonin transporter (SERT), may affect the underlying psoriasis pathology. METHODS: An imiquimod-induced psoriatic mouse model (BALB/c) evaluated brilaroxazine's activity in a topical liposomal-aqueous gel (Lipogel) formulation. Two of the three groups (n = 6 per) underwent induction with 5% imiquimod, and one group received topical brilaroxazine Lipogel (Days 1-11). Assessments included (1) Psoriasis Area and Severity Index (PASI) scores (Days 1-12), skin histology for Baker score based on H&E stained tissue (Day 12), and serum blood collection for serum cytokine analysis (Day 12). One-way ANOVA followed by post hoc Dunnett's t-test evaluated significance (p < 0.05). RESULTS: Imiquimod-induced animal Baker scores were higher versus Sham non-induced control's results (p < 0.001). Brilaroxazine Lipogel had significantly (p = 0.003) lower Baker scores versus the induced Psoriasis group. Brilaroxazine PASI scores were lower (p = 0.03) versus the induced Psoriasis group (Days 3-12), with the greatest effect in the last 3 days. The induced Psoriasis group showed higher Ki-67 and TGF-ß levels versus non-induced Sham controls (p = 0.001). The brilaroxazine Lipogel group displayed lower levels of these cytokines versus the induced Psoriasis group, Ki-67 (p = 0.001) and TGF-ß (p = 0.008), and no difference in TNF-α levels versus Sham non-induced controls. CONCLUSION: Brilaroxazine Lipogel displayed significant activity in imiquimod-induced psoriatic animals, offering a novel therapeutic strategy.

Pulsed dye laser and adjuvant topical therapies for the treatment of port-wine stains: A systematic review.

OBJECTIVES: The current gold standard treatment for port-wine stains (PWS) is pulsed dye laser (PDL). However, multiple treatment sessions may be necessary and complete resolution is often not achieved. Neoangiogenesis can occur soon after treatment and is thought to be a major factor contributing to treatment failure. Adjuvant antiangiogenic topical therapies may therefore improve the efficacy of pulsed dye laser treatment of port-wine stains. MATERIAL AND METHODS: Following PRISMA guidelines, we searched PubMed, Embase, Web of Science, and clinicaltrials.gov using "port-wine stain," "nevus flammeus," "capillary malformation," "sturge weber," and "pulsed dye laser" as keywords and medical subject heading (MeSH) terms. Articles were included if they (1) were a randomized controlled trial (RCT); (2) studied patients with PWS; and (3) investigated topical adjuvant therapies with PDL. Bias was assessed using the Critical Appraisal Skills Programme (CASP) Randomized Controlled Trial Standard Checklist. RESULTS: 1835 studies were identified, with six studies meeting inclusion criteria. The total number of patients studied was 103 (range: 9-23), with 8-36 week follow-up. The average age ranged from 11 to 33.5 years old. Three studies examined adjuvant topical sirolimus (n = 52), two examined timolol (n = 29), and one studied imiquimod (n = 22). Two of three RCTs reported no improvement through colorimetric analysis with topical sirolimus; however, one of these studies did show a significant improvement through Investigator Global Assessment (IGA) score. The last sirolimus study showed significant improvement through digital photographic image scoring (DPIA). Studies examining topical timolol reported no change in PWS appearance compared to placebo. The addition of 5% adjuvant imiquimod cream did lead to significant improvement. A variety of outcome measures were used. Imiquimod and sirolimus led to mild cutaneous adverse events, while timolol caused no side effects. None of the adverse events led to treatment discontinuation. Study quality was moderate in three, high in two, and low in one. CONCLUSION: The efficacy of adjuvant topical therapy was unclear. Limitations included variation in concentration and duration of adjuvant therapies, differences in follow-up time, and inconsistent outcome measure reporting. Given their potential clinical promise, larger prospective studies examining topical adjuvant therapies should be considered.

Efficacy and safety of a 0.05 % nanoencapsulated imiquimod hydrogel for the treatment of actinic cheilitis: Drug release analysis and clinical study.

Actinic cheilitis (AC) is a lip disorder, with no standard treatment. Imiquimod (IMIQ) is an immunomodulator that treat precancerous lesions; however, its commercial form causes severe adverse effects. This study aimed to assess IMQ release from a chitosan hydrogel containing 0.05 % nanoencapsulated (NANO) imiquimod (IMIQ-0.05 %-NANO) and its efficacy in AC treatment. The hydrogels were prepared by incorporating chitosan into polymeric nanocapsules (NCimiq) loaded with IMQ, produced using the interfacial deposition of preformed polymer method. IMQ release was evaluated using automated Franz Cells. A triple-blind randomized controlled trial (49 subjects) compared the efficacy of: IMIQ-0.05 %-NANO, 5 % free imiquimod (IMIQ-5 %), 0.05 % free imiquimod (IMIQ-0.05 %), and placebo hydrogel. The IMIQ-NANO-0.05 % and IMIQ-5 % groups exhibited significantly higher rates of clinical improvement (p < 0.05); however, the IMIQ-5 % group experienced more adverse effects (92.3 % of subjects) compared to other groups (p < 0.05). In conclusion, in the studied sample, IMIQ-NANO-0.05 % was a safe and effective option to treat AC.

Posidonia oceanica (L.) Delile Is a Promising Marine Source Able to Alleviate Imiquimod-Induced Psoriatic Skin Inflammation.

Psoriasis is a chronic immune-mediated inflammatory cutaneous disease characterized by elevated levels of inflammatory cytokines and adipokine Lipocalin-2 (LCN-2). Recently, natural plant-based products have been studied as new antipsoriatic compounds. We investigate the ability of a leaf extract of the marine plant Posidonia oceanica (POE) to inhibit psoriatic dermatitis in C57BL/6 mice treated with Imiquimod (IMQ). One group of mice was topically treated with IMQ (IMQ mice) for 5 days, and a second group received POE orally before each topical IMQ treatment (IMQ-POE mice). Psoriasis Area Severity Index (PASI) score, thickness, and temperature of the skin area treated with IMQ were measured in both groups. Upon sacrifice, the organs were weighed, and skin biopsies and blood samples were collected. Plasma and lesional skin protein expression of IL-17, IL-23, IFN-γ, IL-2, and TNF-α and plasma LCN-2 concentration were evaluated by ELISA. PASI score, thickness, and temperature of lesional skin were reduced in IMQ-POE mice, as were histological features of psoriatic dermatitis and expression of inflammatory cytokines and LCN-2 levels. This preliminary study aims to propose P. oceanica as a promising naturopathic anti-inflammatory treatment that could be introduced in Complementary Medicine for psoriasis.

Supported liquid extraction combined with liquid chromatography tandem mass spectrometry for the quantitative analysis of a TLR7 agonist imiquimod LFX453 in plasma at low picograms per milliliter: Method validation and its application to a pharmacokinetic study in minipig.

Sample preparation is essential for low-level compound determination. In the present work, supported liquid extraction (SLE) was used as sample preparation for the low-level determination of a new TLR7 agonist imiquimod compound, LFX453. Samples were extracted on ISOLUTE® SLE 96-well plates using tert-butyl-methyl ether followed by evaporation and dry residue reconstitution with 150 µl of a mixture of 0.1% formic acid in acetonitrile-water (50/50, v/v). Samples were eluted using a flow rate of 0.750 ml/min on a C18 column (50 × 2.1 mm, 2.7 µm) with a mobile phase consisting of 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). Tandem mass spectrometry was used to analyze the samples in positive mode. The method run time was 6.5 min, and the low limit of quantification was 1.00 pg/ml with 0.100 ml of minipig plasma. Intra-run and inter-run precision and accuracy were within the acceptance criteria at four concentration levels over a concentration ranging from 1.00 to 200 pg/ml. There was no matrix effect and recovery, three freeze-thaw cycles and incurred samples reanalysis were validated. The method was successfully applied for measuring LFX453 in minipig plasma after application on minipig skin.

Hydroxychloroquine exacerbates imiquimod-induced psoriasis-like dermatitis through stimulating overexpression of IL-6 in keratinocytes.

OBJECTIVE: Hydroxychloroquine (HCQ) is a US Food and Drug Administration (FDA)-approved treatment for systemic lupus erythematosus (SLE) through inhibition of antigen presentation and subsequent reduction in T cell activation. Psoriasis relapse after antimalarial therapy have been reported in up to 18% of patients with psoriasis. Here, we explored the role of HCQ on exacerbating dermatitis utilizing an imiquimod (IMQ)-induced psoriasis-like dermatitis mouse model. METHODS: Thirty-six C57BL/6 female mice were divided into six groups: wild-type control, IMQ-Only, pre-treat HCQ (30 mg/kg and 60 mg/kg HCQ), and co-treat HCQ with IMQ (30 mg/kg and 60 mg/kg HCQ). Besides control, all were topically treated with IMQ for 5 days. Pharmacological effects and mechanisms of HCQ were assessed by clinical severity of dermatitis, histopathology, and flow cytometry. HaCaT cells were co-treated with both HCQ and recombinant IL-17A, followed by the detection of proinflammatory cytokine expression and gene profiles through enzyme-linked immunosorbent assay and next-generation sequencing. RESULTS: In the pre-treated and co-treated HCQ groups, skin redness and scaling were significantly increased compared to the IMQ-Only group, and Th17 cell expression was also upregulated. Acanthosis and CD11b+IL23+ dendritic cell (DC) infiltration were observed in the HCQ treatment group. IL-6 overexpression was detected in both the HaCaT cells and skin from the experimental mice. Psoriasis-related genes were regulated after being co-treated with HCQ and recombinant IL-17A in HaCaT cells. CONCLUSIONS: HCQ exacerbates psoriasis-like skin inflammation by increasing the expression of IL-6, stimulating DC infiltration, and promoting Th17 expression in the microenvironment of the skin. KEY MESSAGES: This study provided possible mechanisms for inducing psoriasis during HCQ treatment through an animal model.

Low-concentration imiquimod treatment promotes enhanced skin barrier functions through epidermal melanization reaction regulation.

The primary function of the skin is to form a mechanical, permeability, antimicrobial, and ultraviolet radiation barrier, which is essential for maintaining physiological homeostasis. Our previous studies demonstrated that cutaneous pigmentation could promote skin barrier function in addition to providing anti-ultraviolet irradiation defense. The present study aimed to develop a new regimen that enhances skin barrier function by regulating skin pigmentation using low-concentration imiquimod. Results showed that topical application of low-concentration imiquimod effectively induced skin hyperpigmentation in the dorsal skin and external ear of mice without inducing inflammatory cell infiltration. An in vitro study also revealed that low-concentration imiquimod did not induce any cytotoxic effects on melanoma cells but triggered excessive melanin synthesis. In coculture systems, low-concentration imiquimod was noted to increase tyrosinase activity in a broader cellular context, revealing the potential role of neighboring cells in melanin production. The next-generation sequencing result indicated that PKCη and Dnm3 might regulate melanin synthesis and release during imiquimod treatment. Overall, our study presents new insights into the regulation of melanin production by low-concentration imiquimod, both in a mice model and cultured cells. Furthermore, our study highlights the potential benefits of imiquimod in promoting melanin synthesis without causing skin disruptions or inducing inflammation, validating its potential to serve as a method for enhancing skin barrier functions by regulating the epidermal melanization reaction.

Eucalyptus oil nanoemulsion for enhanced skin deposition of fluticasone propionate in psoriatic plaques: A combinatorial anti-inflammatory effect to suppress implicated cytokines.

Psoriasis is a chronic inflammatory skin disease that affects patients' quality of life. This study aimed to enhance the efficacy of topical application of fluticasone propionate (FP) using a eucalyptus oil-based nanoemulsion, an oil possessing anti-inflammatory activity and extracted from the leaves, fruits, and buds of Eucalyptus globulus or Eucalyptus maidenii, to improve the skin deposition of FP and aid its anti-inflammatory effect. Box-Behnken design was employed to optimize NE formulations, which were characterized for globule size, zeta potential, polydispersity index, rheological behavior, microscopic morphology, ex vivo skin permeation/deposition, and in vivo efficacy using imiquimod-induced psoriatic lesions. The optimized formulation depicted a droplet size of 188 ± 22.4 nm, a zeta potential of -17.63 ± 1.66 mV, and a viscosity of 204.9 mPa s. In addition to the increased FP retention in different skin layers caused by the NE and the reduced PASI score compared to the marketed cream, the levels of inflammatory cytokines IL-1α, IL-6, IL17a were markedly lowered, indicating the improved anti-psoriatic curable efficacy of the optimized formulation in comparison to the FP-marketed product.

Evaluation of Clobetasol and Tacrolimus Treatments in an Imiquimod-Induced Psoriasis Rat Model.

Psoriasis is a chronic inflammatory skin disorder characterized by keratinocyte hyperproliferation, inflammation, and aberrant differentiation. Imiquimod-induced psoriasis in rodent models has been widely used to study the pathogenesis of the disease and evaluate potential therapeutic interventions. In this study, we investigated the efficacy of two commonly used treatments, Clobetasol and Tacrolimus, in ameliorating psoriatic symptoms in an Imiquimod-induced psoriasis Wistar rat model. Interestingly, rat models are poorly evaluated in the literature despite rats displaying several advantages in evaluating pharmacological substances. Psoriasis-like skin lesions were induced by topical application of Imiquimod cream on shaved dorsal skin for seven consecutive days. Following induction, rats in the treatment groups received either a Clobetasol or Tacrolimus ointment once daily for one week, while the control group did not receive any application. Disease severity was assessed using clinical scoring, histological examination, and measurement of proinflammatory cytokine levels. Both Clobetasol and Tacrolimus treatments significantly reduced psoriatic lesion severity compared to the control group. Clinical scoring revealed a decrease in erythema, scaling, transepidermal water loss, and thickness of skin lesions in both treatment groups with a more marked effect with Clobetasol. Histological analysis demonstrated reduced epidermal hyperplasia in treated animals compared to controls. Furthermore, Clobetasol led to a significant reduction in the expression levels of the interleukin-17 (IL-17a and IL-17f) proinflammatory cytokines in lesioned skin. Overall, our findings demonstrated the therapeutic efficacy of both Clobetasol and, in a modest manner, Tacrolimus in attenuating Imiquimod-induced psoriasis-like symptoms in a rat model. These results support the clinical use of these agents in the management of psoriasis and mitigating psoriatic inflammation. They also provide insights into the use of rats as a relevant species for the Imiquimod-induced psoriasis model.

Therapeutic Effect of Lecigel, Cetiol®CC, Activonol-6, Activonol-M, 1,3-Propanediol, Soline, and Fucocert® (LCAA-PSF) Treatment on Imiquimod-Induced Psoriasis-like Skin in Mice.

The individual ingredients of 1,3-Propanediol, Soline, and Fucocert® (PSF) are often used as cosmetic formulations in skin care. In addition, the mixture of Lecigel, Cetiol®CC, Activonol-6, and Activonol-M (LCAA) is often used as a cosmetic base. However, whether the combination of LCAA with PSF (LCAA-PSF) exerts a therapeutic effect on psoriasis remains unclear. In this study, mice induced with imiquimod (IMQ) were divided into three groups and administered 100 mg/day of LCAA, 100 mg/day of LCAA-PSF, or Vaseline on the dorsal skin of each mouse. Weight-matched mice treated with Vaseline alone were used as controls. Hematoxylin and eosin (H&E) staining and enzyme-linked immunosorbent assay(ELISA) were used to assess tissue morphology and inflammatory cytokines. RNA sequencing analysis was used to predict the mechanism underlying the action of LCAA-PSF against psoriasis, while immunohistochemical analysis validation was used to identify pertinent molecular pathways. The results demonstrated that LCAA-PSF alleviated IMQ-induced keratinocyte differentiation/ proliferation bydecreasingthe serum levels of inflammatory cytokines such as IL-6, TNF-α, IL-23, and IL-17A and the epidermisof TGFß, Ki67, CK5/6, and VEGF expression, which is associated with angiogenesis and keratinocyte differentiation/ proliferation. These findings highlight the antipsoriatic activity of LCAA-PSF in a psoriasis-like mouse model and suggest this may occurvia the inhibition of inflammatory factor secretionand the TGFß-related signal pathway.